U.S. Pat. No. 4,289,845 shows resist systems comprising a novolac matrix polymer and a polysulfone modifier.
U.S. Pat. No. 4,398,001 shows the use of a novolac matrix and a sulfone additive which is a poly(ether pentene solfone) (PEPS).
Neither of these two prior art patents discloses dry development, but only wet development.